1. Field of the Invention
This invention relates generally to electric motors, and particularly to a variable speed electromagnetic impulse motor.
2. Description of the Prior Art
Electromagnetic motors are well known and have been long proposed. See, for example, U.S. Pat. Nos. 127,369, issued May 28, 1872 to W. H. Richardson, and 722,042, issued Mar. 3, 1903 to Angel Pol Y Aguirre. These known electromagnetic motors generally propose to use permanent magnets as a stationary field and intermittently energize rotating electromagnets which interact with the permanent magnets to cause rotation of the rotor of the motor. The intermittent energizing of the electromagnets is conventionally achieved as by using the rotor of the motor as a timing disc, which creates speed control problems. Accordingly, these known electromagnetic motors are generally single speed affairs, as is the case with the impulse motor disclosed in U.S. Pat. No. 1,764,921, issued June 17, 1930 to A. Wiedner. The device of the latter mentioned reference arranges the electromagnets in a stationary field, with the permanent magnets being mounted on the armature.
U.S. Pat. No. 2,922,943, issued Jan. 26, 1960 to H. Rupp, discloses an impulse motor that proposes to provide variable speed operation by use of an oscillating tank circuit which controls the duration of pulses sent to the electromagnets of the motor. This approach, however, is limited in use since the tank circuit employed must be capable of withstanding the electrical power being supplied to the electromagnets of the impulse motor.